Alright, I just tested that setting and it doesn't work.

https://i.imgur.com/MYsDSOV.png

I tested because I was porting memories from Claude Code to Codex, so I might as well test. I obviously still have subscription days remaining.

There is another comment in this thread linking a GitHub issue that discusses this. The GitHub issue this whole HN submission is about even says that Anthropic hides thinking blocks.